Pope Boniface IX died on October 1, 1404. Cardinal Cosmato Gentile de' Migliorati was elected his successor on October 17, 1404 and took the name of Innocent VII. During this sede vacante, the Roman Obedience of the Sacred College of Cardinals had only twelve members. Nine of the twelve participated in the election of Innocent VII. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

Pope Innocent VII died on November 6, 1406. Cardinal Angelo Correr was elected his successor on November 30, 1406 and took the name of Gregory XII. During this sede vacante, the Roman Obedience of the Sacred College of Cardinals had eighteen members, fourteen of which participated in the election of Gregory XII. Cardinal Ludovico Fieschi had abandoned the Roman Obedience and had been recognized as cardinal by the Antipope Benedict XIII. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

(1) To end the schism, resigned through his procurator Carlo Malatesta, on July 4, 1415 in the Council of Constance. The Council granted him the title of cardinal-bishop of Porto e Santa Rufina and the rank immediately after the pope. Died on October 18, 1417 in Recanati.

The Council of Pisa was summoned by the cardinals to end the Great Schism. It convened on March 25, 1409. After deposing both Benedict XIII and Gregory XII, on June 5, 1409, the twenty-three cardinals who supported the Council entered a conclave on June 15. Eleven days later, on June 26, they elected Pietro Filargis, O.F.M., who assumed the name Alexander V. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

The following cardinal did not participate in the conclave:
-Ludovico Fieschi, deacon of S. Adriano. (1)

(1) Abandoned the obedience of Innocent VII on October 22, 1404 and joined that of Benedict XIII on May 11, 1405. After the election of Alexander V on June 26, 1409, at the Council of Pisa, he adhered to the obedience of this antipope.

Antipope Alexander V died at Bologna on May 3, 1410. The cardinals who had adhered to the Council of Pisa met in Bologna for a conclave to elect his successor. They chose Baldassare Cossa on May 17, 1410. He took the name John XXIII. The twenty-three original cardinals who convened the Council were now reduced by two, Pietro Filargis, O.F.M. (Alexander V) and Pierre Blain, deacon of S. Angelo in Pescheria, who died on December 12, 1409. The Pisan Obedience had, however, gained another adherent, Ludovico Fieschi, a creation of Urban VI, who submitted to Alexander. The number of cardinal-electors was twenty two, but five of them were absent from the conclave. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

Twenty-three cardinals joined with six representatives from each of the five nations (England, France, Germany, Italy and Spain) at the Council of Constance to conduct a unique conclave. Cardinal Oddone Colonna was elected Pope Martin V on November 11, 1417. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

Prelates of the five nations who joined the cardinals in the conclave:England:
-Richard Clifford, bishop of London.
-Nicholas Bubbewyth, bishop of Bath and Wells.
-John Catterick, bishop of Conventry and Lichfield.
-John Wakering, bishop of Norwich.
-Thomas, abbot of St. Mary's monastery, York.
-Thomas, dean of York.

France:
-Jean de Rochetaillée, patriarch of Constantinople (cardinal, 1426).
-Guillaume de Boisratier, archbishop of Bourges.
-Jacques de Gelu, archbishop of Tours.
-Jean des Bertrandis, bishop of Geneva.
-Robert, abbot of Cluny.
-Gauthier Crassi, prior of the Order of Saint John of Jerusalem.

Antipope Benedict XIII died on May 23, 1423 in Peñíscola, Aragón, Spain, at 95 years of age. He had made his four pseudocardinals promise that they would elect a successor after his death. Three of them met in conclave and elected Gil Sánchez Muñoz, provost of Valencia and archpriest of Teruel, Spain, who took the name Clement VIII. One of the pseudocardinals, Jean Carrier, was in Armagnac, France, and arrived after the election had taken place.

Pseudocardinal Jean Carrier, title of S. Stefano in Monte Celio, who was absent from the election of Antipope Clement VIII, decided, after consulting theologians and canonists, that that election was invalid because "it was done by liers, thieves and excomunicated persons" and declared that he alone had the right to fill the Holy See. Carrier gathered a notary and several witnesses in Armagnac, France, and designated pope Bernard Garnier, a sacristan of Rodez, France, and consecrated him. He took the name Benedict XIV. Shortly after his election this antipope disappeared from history and not even the date of his death is known. (Anselmo Gascón de Gotor, Pedro de Luna, el pontífice que no cedió. Madrid: Biblioteca Nueva, 1956).

Pope Martin V died on February 20, 1431. Cardinal Gabriele Condulmer, Can. Reg. of Saint Augustine of S. Giorgio in Alga, was elected his successor on March 3, 1431 and took the name of Eugenius IV.
During this sede vacante, there were some twenty-three men who were cardinals, but the College itself considered that it had a valid membership
of nineteen. Juan Casanova, O.P., and Guillaume Raguenel de Montfort had been created without publication (an innovation of Pope Martin V). A third, Domenico Capranica, had been created and published a cardinal, but had not yet been received by the Sacred College of Cardinals. In addition, one other cardinal, Philip Repington, Can. Reg. of Saint Augustine, was in complete retirement in England, and had not been acknowledged as a member of the college since at least 1409. Consequently, the college itself considered that it had a valid membership of nineteen. Of the nineteen cardinals, six were absent entirely from the election. The remaining thirteen were the electors present in the conclave. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

The Council of Basel (1431-1449) deposed Pope Eugenius IV and, in an irregular election, chose Amedeo VIII, duke of Savoie, to replace him. Amadeus was also the founder and superior of the order of knights-hermits of St. Maurice in Ripaillie, diocese of Gèneve, Switzerland. He was elected by one cardinal, eleven bishops, seven abbots, and fourteen theologians and doctors and took the name Felix V. Consecrated and crowned in Basel on July 24, 1440, he abdicated on April 7, 1449 and was created cardinal bishop of Sabina by Pope Nicholas V on that same day (or on April 23). He died in Gèneve on January 7, 1451.

Pope Eugenius IV died on February 23, 1447. Cardinal Tommaso Parentucelli was elected his successor on March 6, 1447 and took the name of Nicholas V.
During this sede vacante, there were twenty-seven men who had been created and published as cardinals. However, one of them, Louis Aleman, C.R.S.J., had been excommunicated and deprived of his cardinalate by Pope Eugenius IV on December 11, 1440 because of his active participation in the Council of Basel. He was reinstated by Pope Nicholas V on December 19, 1449. Of the twenty-six valid cardinal-electors, eighteen attended the conclave while eight were absent. The electoral meeting was held in the Dominican house next to the church of Santa Maria sopra Minerva. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

Pope Nicholas V died on March 24, 1455. Cardinal Alfonso Borja was elected his successor on April 8, 1455 and took the name of Callistus III. At the moment of the death of Nicholas V, there were twenty-two living cardinals. But one, Zbigniew z Oleśnicy, died in sede vacante on April 1, 1455. Fifteen of the twenty-one cardinals participated in the conclave. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

Pope Callistus III died on August 6, 1458. Cardinal Enea Silvio Piccolomini was elected his successor on August 19, 1458 and took the name of Pius II. At the time of the death of Pope Callixtus III there were twenty-seven living cardinals. But one, Cardinal Domenico Capranica, died two days before the beginning of the conclave on August 14, 1458. Eight others did not attend the conclave. (Notes provided by Dr. Francis A. Burkle-Young, author of Passing the Keys.)

Pope Pius II died on August 14, 1464. Cardinal Pietro Barbo was elected on August 30, 1464 and took the name Paul II. At the time of the death of the pope there were twenty-nine living cardinals. Nineteen cardinals attended the conclave and ten were absent.

Pope Paul II died on July 26, 1471. Cardinal Francesco della Rovere, O.F.M.Conv. was elected on August 9, 1471 and took the name Sixtus IV. At the time of the death of Pope Paul II there were twenty-five living cardinals and eighteen of them participated in the conclave.

Pope Sixtus IV died on August 12, 1484. Cardinal Giovanni Battista Cibo was elected on August 29, 1484 and took the name Innocent VIII. At the time of the death of Pope Sixtus IV there were thirty-two living cardinals. Twenty-five cardinals participated in the conclave and seven were absent.

Pope Innocent VIII died on July 25, 1492. Cardinal Rodrigo de Borja y Borja was elected on August 11, 1492 and took the name Alexander VI. At the time of the death of Pope Innocent VIII there were twenty-seven living cardinals. Twenty-three cardinals participated in the conclave and four were absent.

The following cardinals did not participate in the conclave:
-Lluís Joan del Milà, title of Ss. IV Coronati, bishop of Lérida, Spain.
-Pedro González de Mendoza, title of S. Croce in Gerusalemme, archbishop of Toledo, Spain.
-André d'Espinay, title of Ss. Silvestro e Martino ai Monti, archbishop of Bordeaux, and Lyon, France.
-Pierre d'Aubusson, O.S.Io.Hieros., deacon of S. Adriano.